反应详情

3-Methoxyestra-2,5(10)-dien-17β-ol 1 (2.0 g, 6.9 mmol) was added to a solution consisting of tetrahydofuran (15 ml), DMSO (5 ml) and t-BuOK (20.7 mmol). The resultant solution was stirred at ambient temperature for 10 hours at which time the solution was concentrated to Å5 ml and chromatographically filtered with 50% ethylether/petroleum ether (light) through 10 g of silica gel. The subsequent dimethyl sulfoxide (DMSO) free -powder was flash chromatographed affording 4 as white needles (1.30 g, 65% conversion, 91% based on recovered 1), Alternatively, crystallization by selective seeding (ether/methanol) was utilized, thereby circumventing chromatographic purification. 1H NMR (d6-acetone) δ4.629 (s, 1H), 3.505 (t, J=8.09 Hz, 1H), 3.431 (s, 3H), 2.15-0.98 (complex, 20H), 0.644 (s, 3H). 13C NMR (CDCl3) δ156.71, 126.56, 123.88, 96.55, 81.31, 54.19, 50.18, 46.03, 39.91, 37.54, 30.64, 30.58, 30.21, 27.71, 27.17, 25.67, 25.24, 23.22, 11.37.

1. concentrationwas concentrated to Å5 ml
2. filtrationchromatographically filtered with 50% ethylether/petroleum ether (light) through 10 g of silica gel
3. customchromatographed